Commentary: Musicians' online performance during auditory and visual statistical learning tasks

A commentary on: Musicians' Online Performance during Auditory and Visual Statistical Learning Tasks by Mandikal Vasuki, P. R., Sharma, M., Ibrahim, R. K., and Arciuli, J. (2017). Front. Hum. Neurosci. 11:114. doi: 10.3389/fnhum.2017.00114 Statistical learning (SL) is the extraction of the underlying statistical structure from sensory input (Frost et al., 2015). The extent to which this ability is domain-general (with a single central mechanism underpinning SL in any modality) or domain-specific (where the SL mechanism differs by modality) remains a central question in statistical learning (Frost et al., 2015), and two approaches have been adopted to tackle this. First is to examine the extent to which predominantly domain-specific skills such as language proficiency (Arciuli and von Koss Torkildsen, 2012) and musical expertise (Schön and François, 2011), and domain-general skills such as working memory and general IQ (Siegelman and Frost, 2015), correlate with SL ability. Second is to compare SL performance across modalities, or even examine cross-modal transfer (Durrant et al., 2016). Mandikal Vasuki et al. (2017) (and the sister paper: Mandikal Vasuki et al., 2016) make an important contribution by adopting both of these approaches. They compare auditory and visual SL using the Saffran triplet learning paradigm (Saffran et al., 1999) in musicians and non-musicians. The three key findings are that musicians are better than non-musicians at segmentation of auditory stimuli only, there is no correlation between auditory and visual performance, and that auditory performance is better overall. This last result could be due to privileged auditory processing of sequential stimuli (Conway et al., 2009), or it could just reflect differences in perceptual or memory capabilities across modalities. However, the fact that SL performance in one modality does not predict performance in another is hard to explain if a single mechanism underlying both is posited. Combined with the fact that overall better performance was found in musicians only in the auditory modality, a domain-specific SL mechanism seems to offer the most parsimonious explanation of this data

Schema-conformant memories are preferentially consolidated during REM sleep

Memory consolidation is most commonly described by the standard model, which proposes an initial binding role for the hippocampus which diminishes over time as intracortical connections are strengthened. Recent evidence suggests that slow wave sleep (SWS) plays an essential role in this process. Existing animal and human studies have suggested that memories which fit tightly into an existing knowledge framework or schema might use an alternative consolidation route in which the medial prefrontal cortex takes on the binding role. In this study we sought to investigate the role of sleep in this process using a novel melodic memory task. Participants were asked to remember 32 melodies, half of which conformed to a tonal schema present in all enculturated listeners, and half of which did not fit with this schema. After a 24-h consolidation interval, participants were asked to remember a further 32 melodies, before being given a recognition test in which melodies from both sessions were presented alongside some previously unheard foils. Participants remembered schema-conformant melodies better than non-conformant ones. This was much more strongly the case for consolidated melodies, suggesting that consolidation over a 24-h period preferentially consolidated schema-conformant items. Overnight sleep was monitored between the sessions, and the extent of the consolidation benefit for schema-conformant items was associated with both the amount of REM sleep obtained and EEG theta power in frontal and central regions during REM sleep. Overall our data suggest that REM sleep plays a crucial role in the rapid consolidation of schema-conformant items. This finding is consistent with previous results from animal studies and the SLIMM model of Van Kesteren, Ruiter, Fernández, and Henson (2012), and suggest that REM sleep, rather than SWS, may be involved in an alternative pathway of consolidation for schema-conformant memories. Copyright © 2015. Published by Elsevier Inc

A more comprehensive and commanding delineation: Mary Shelley's narrative strategy in Frankenstein

This thesis argues that the first edition of Frankenstein challenges conventional reading by employing what Simpson in Irony and Authority in Romantic Poetry calls Romantic irony, where the absence of a stable 'metacomment' precludes an authoritative reading. The novel hints at such readings but prevents them. The insights offered by Tropp's Mary Shelley's Monster, Baldick's In Frankenstein's Shadow, Poovey's The Proper Lady and the woman writer and Swingle's, 'Frankenstein's Monster and its Relatives: Problems of Knowledge in English Romanticism' are considered, but none recognises the full implications of the instability deriving from multiple first- person narratives. Clemit's The Godwinian Navel acknowledges the novel's indeterminacy, but reads a specific ideological purpose in it. Paradise Last provides a language to describe the relationship between the monster and Frankenstein, but proves too unstable to fix identity or establish moral value. Similarly, Necessity ultimately fails to provide a stable explanation in terms of cause and effect. The status of nature shifts between foreground and background, never allowing final definition. These uncertainties destabilise knowledge which is compromised by its provisional nature: no authoritative reading is possible, yet the novel has narrative coherence. The reader is encouraged to try to develop a reading the structure prevents. The radical nature of the first edition is highlighted by comparison with the 1831 edition, which removes much of the ambivalence and gives the novel a clearer morality. The novel challenges conventional methods of deriving authority by disturbing the reader's orthodox orientation in the world around him' (Simpson) in order to afford 'a point of view to the imagination for the delineation of human passions more comprehensive and commanding than any which the ordinary relations of existing events can yield' (Mary Shelley)

Overnight consolidation aids the transfer of statistical knowledge from the medial temporal lobe to the striatum

Sleep is important for abstraction of the underlying principles (or gist) which bind together conceptually related stimuli, but little is known about the neural correlates of this process. Here, we investigate this issue using overnight sleep monitoring and functional magnetic resonance imaging (fMRI). Participants were exposed to a statistically structured sequence of auditory tones then tested immediately for recognition of short sequences which conformed to the learned statistical pattern. Subsequently, after consolidation over either 30min or 24h, they performed a delayed test session in which brain activity was monitored with fMRI. Behaviorally, there was greater improvement across 24h than across 30min, and this was predicted by the amount of slow wave sleep (SWS) obtained. Functionally, we observed weaker parahippocampal responses and stronger striatal responses after sleep. Like the behavioral result, these differences in functional response were predicted by the amount of SWS obtained. Furthermore, connectivity between striatum and parahippocampus was weaker after sleep, whereas connectivity between putamen and planum temporale was stronger. Taken together, these findings suggest that abstraction is associated with a gradual shift from the hippocampal to the striatal memory system and that this may be mediated by SWS

Studying the effects of thalamic interneurons in a thalamocortical neural mass model

Neural mass models of the thalamocortical circuitry are often used to mimic brain activity during sleep and wakefulness as observed in scalp electroencephalogram (EEG) signals [1]. It is understood that alpha rhythms (8-13 Hz) dominate the EEG power-spectra in the resting-state [2] as well as the period immediately before sleep [3]. Literature review shows that the thalamic interneurons (IN) are often ignored in thalamocortical population models; the emphasis is on the connections between the thalamo cortical relay (TCR) and the thalamic reticular nucleus (TRN). In this work, we look into the effects of the IN cell population on the behaviour of an existing thalamocortical model containing the TCR and TRN cell populations [4]. A schematic of the extended model used in this work is shown in Fig.1. The model equations are solved in Matlab using the Runge-Kutta method of the 4th/5th order. The model shows high sensitivity to the forward and reverse rates of reactions during synaptic transmission as well as on the membrane conductance of the cell populations. The input to the model is a white noise signal simulating conditions of resting state with eyes closed, a condition well known to be associated with dominant alpha band oscillations in EEG e.g. [5]. Thus, the model parameters are calibrated to obtain a set of basal parameter values when the model oscillates with a dominant frequency within the alpha band. The time series plots and the power spectra of the model output are compared with those when the IN cell population is disconnected from the circuit (by setting the inhibitory connectivity parameter from the IN to the TCR to zero). We observe (Fig. 2 inset) a significant difference in time series output of the TRN cell population with and without the IN cell population in the model; this in spite of the IN having no direct connectivity to and from the TRN cell population (Fig. 1). A comparison of the power spectra behaviour of the model output within the delta (1-3.5Hz), theta (3.75-7.5Hz), alpha (7.75-13.5Hz) and beta (13.75-30.5Hz) bands is shown in Fig. 2. Disconnecting the IN cell population shows a significant drop in the alpha band power and the dominant frequency of oscillation now lies within the theta band. An overall ‘slowing’ (left-side shift) of the power spectra is observed with an increase within the delta and theta bands and a decrease in the alpha and beta bands. Such a slowing of EEG is a signature of slow wave sleep in healthy individuals, and this suggests that the IN cell population may be centrally involved in the phase transition to slow wave sleep [6]. It is also characteristic of the waking EEG in Alzheimer’s disease, and may help us to understand the role of the IN cell population in modulating TCR and TRN cell behaviour in pathological brain conditions

British Sleep Society: the COVID-19 pandemic response

The current pandemic caused by a novel coronavirus, named COVID-19, holds the entire world to ransom. A proportion of the infected patients becomes critically ill, with millions being infected and hundreds of thousands who have died so far. In some countries, national lockdown restrictions are being slowly lifted, but the World Health Organization (WHO) still registers increasing numbers of confirmed COVID-19 infections across its membership states. Against this background, the BSS brought together doctors from the respiratory and critical care response teams in Wuhan, China and London, UK in a webinar to exchange their knowledge and expertise and discuss current best practice in the management of patients with COVID-19. Following their presentations, sleep experts from the Executive Committee of the BSS discussed the impact of the pandemic and lockdown on sleep and shared practical advice regarding sleep health

Photo mementos: designing digital media to represent ourselves at home

We examine photos in the family home as examples of mementos, cherished objects kept in memory of a person or event. In a ‘memory tour’, we asked participants to walk us through their family home selecting and discussing significant mnemonic objects. With each personal narrative we recorded memento location, i.e. the room, place within the room and any nearby objects. Although photos were not the most popular mementos, when chosen they were highly significant, and often unique. These photo mementos were usually not representational but symbolic, where only the owner knows their many layers of meaning. Photos from different times in the person’s life were strategically placed in different rooms. Their location afforded different functions, e.g. photo mementos in family spaces reinforced family bonds, photo mementos in personal spaces were for immersive reminiscing, whereas those in public rooms had an aesthetic value and to spark conversations with visitors. Finally photo mementos were rarely isolated: they were clustered in displayed albums or stored with other memorabilia in boxes or drawers to represent a stage in life. We explore the implications of these findings by designing potential new home photo technologies, looking at how new designs might support the types of behaviours observed. Through four conceptual designs we examine how photo technology might integrate into the practices and aesthetic of the family home. The concepts led to a set of concluding considerations that need to be taken into account when designing new forms of display technology that are part of a larger domestic photo system